The present invention relates to a navigation system and a navigation method, for executing a guidance with speech and display and in particular to a navigation system and a navigation method, for outputting plural guidances for guidance events that have happened in an overlapping manner, and inhibiting a guidance that is meaningless to a user.
In a vehicle navigation system for use in executing a path-guidance up to a destination, a guidance to a user, such as an approach to a crossover point, speeding, and receipt of traffic information, is often executed by means of speech and a screen display. A function has been known whereby a direction in which a user makes a turn is shown by means of a screen and speech, for example, immediately before a vehicle comes to a crossover point. Speech-outputting and screen display are executed whenever necessary on a event-by-event basis every time an event happens, the event being the cause thereof. For this reason, if a screen display based on a certain event is in the course of execution, and concurrently, another event on which another display is to be executed happens, this will lead to a situation where plural display requests are accumulated as a list. Accordingly, in the case where displays are sequentially shown in the order in which events have happened, it follows that the next display is shown after completion of an immediately preceding event. In consequence, timing of outputting speech and a screen display is provided after the vehicle has passed a location where the speech and the screen display are to be outputted, and therefore, there is a possibility that a guidance that is meaningless to a user is executed. To take an example, if speeding occurs in the course of the display of a guidance on a crossover point, and attention-attracting speech is outputted after completion of the display of the guidance on the crossover point, it is conceivable that the vehicle has already largely passed a location where the speeding occurred.
Accordingly, a technology for controlling plural guidances for a user has been proposed.
For example, with a navigation system disclosed in Japanese Unexamined Patent Application Publication No. 2002-236029, if the necessity of outputting a speech guidance having higher priority arises in the course of a certain speech guidance being outputted, the guidance being outputted at present is interrupted, and the speech guidance having higher priority is outputted.
Further, with a navigation system disclosed in Japanese Unexamined Patent Application Publication No. 2006-267328, the order of speech-guidance priorities are pre-decided for every speech-guidance types, and in the case where a speech-guidance that is about to be outputted at present is outputted, determination is made on whether or not overlapping by a speech-guidance having higher priority will occur by a completion time of the outputting. If the overlapping by the speech-guidance having higher priority occurs, the speech guidance that is about to be outputted at present is not executed. Thereby, a speech-guidance having lower priority is prevented from being interrupted by the speech-guidance having higher priority.